Improvement in elevators



J 8. EM. D W I N.

Elevators.

Patented May 20,1873.

5 E E E E N W AM FHOTO-UTHGGRAPHIC co. Nmfosswmzls mam-s.)

UNITED STATES PATENT OFFICE JAMES S, BALDWIN, OF NEWARK, NEW JERSEY.

IMPRQVEMENT IN ELEVATORS.

Specification forming part of Letters Patent No. 138,985, dated May 20,1873; application filed March 17, 1873.

To all whom it may concern:

Be it known that I, J. S. BALDWIN, of Newark, county of Essex and Stateof New Jersey, have invented certain new and useful Improvements inElevators,of which the following is a specification:

The nature of my invention relates to a method of regulating the speedof elevators; and consists in attaching to the pulleys and drum pumpsthe piston of which is attached to the former, and which keeps a body offluid circulating around in a chamber, the flow of the liquid beingcontrolled by a valve which will close as soon as the current becomestoo rapid, and thus check the motion of the descending body.

Figure 1 represents my invention as applied to an elevator for thepurpose of checking the descent of the car.

a represents the drum of an elevator, which is operated by the elevatingmechanism in any suitable manner, and which is secured to the piston ofa rotary pump inclosed in the shell 0, so that when the drum isrevolved, to either raise or lower the car, or any weight attached toit, it will cause the piston to revolve with it. Inclosed in the shellis a quantity of oil, water, or any suitable fluid, which, as the pistonrevolves, is forced'around in the shell, passing through the opening inthe partition 0. The opening 0 is controlled by an elastic or 'othervalve, 2', which allows the liquid to flow freely through, while the caror weight attached to the drum is being elevated, but in descending, assoon as the piston begins to revolve too rapidly, the pressure from theincreased rapidity causes the valve to close and thus stop or checkthemotion of the body. Passing through the shell, and controllinganopening through thus serves to check the motion in the same I do notconfine myself to the use of or claim as my invention any particularform of pump; any of the known kinds of pumps or hydraulic machineswhich will keep the fluid circulating around in the shell may be usedfor the purpose.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is

1. The method of regulating the speed of elevators by connectinghydraulic pumps with the several pulleys or drums, substantially as setforth.

2. The pump connected to the drum and pulley of an elevator, so as tocheck its speed substantially as set forth.

3. In combination with the elevator, the shells 0 in which the rotarypistons operate, having partitions e, automatic valves c, drums, andpulleys, substantially as shown and described.

4. The automatic valve 6, provided with valverod k, for the purpose ofstarting the elevator, substantially as shown and described.

In testimony that I claim the foregoing as my invention I hereunto afixmy signature this 14th day of March, 1873.

. JAMES S. BALDWIN.

- Witnesses:

S. A. BALDWIN, S. BALDWIN.

